HORN EXPEDITION — NARRATIVE. 53 



obviniis reason that the loose saiul near the surface simply falls in and obliterates 

 tlie bun'uw as the animal passes along, so that it is necessary to bo able to follow 

 their tracks on the surface, and this the ])lacks always tell you that they can only 

 do after I'ain. It must be confessed that t.liis is not an altogether satisfa.ctoi'y 

 explanation, but it is one always given by the blacks. Tiie latter will folhjw any 

 track up on dry or wet sand, and there can be no dilliculty whatever in their 

 detecting the track of m, Notoryctes however dry the sand is. I fancy that the real 

 explanation lies in the fact that the Ijlacks catch the beast on the surface when 

 they happen, by chance, to come acioss it, and that, fur sonu^ reason, it is most 

 frequently seen on the surface shortly after rain. 



It is a curious feature about Notoi'yctes that though absolutely Ijlind still 

 it norm.ally spends a part of its time on the surface^ and the complete loss of eyes 

 externally is, no doubt, to be as.sociated with the fact that it is constantly 

 burrowing in loo.se anil often hot .sand, the grains of which would, if it had eyes, 

 be a fruitful source of irritation. 



The a.llinities of Notoryctes to (jther foi'uis of marsupials are .somewhat obscure, 

 but they evidently lie with the Dasyurid;e rather than with any other family. 



It is somewhat diihcult to understand the remarkable modification evidently 

 undei'gone by Notoryctes, whereby it has become adapted to its present mode of 

 life. The modilication in regard, for example, to its complete loss of eyes on the 

 suii'ace, and its shovel-shaped feet are evidently correlated, not only with its 

 burrowing haljits, but with the fact that it burrows in soft, loose, sandy country. 

 If this modification to adapt it to a burrowing habit has taken place during the 

 period (since Pliocene times) in which the central area of the continent has assumed 

 its present desiccated condition, then it is somewhat diilicult to understand how 

 this one form has become so much modified in the time which has only served to 

 produce slight modifications amongst members oi other famili(;s, such as the 

 DasyuridiB. On the other liand, and this is perhaps the most ))roljable state of 

 the case, Notoryctes may be the one (as far as yet known) surviving representative 

 of a once more widely dispersed Ijurrowing and mole-like marsupial, which, for 

 some reason, has been left stranded in the central region and has elsewhere dis- 

 appeared. It is not difiicult to undcsrstand how Notoryctes — at the best an animal 

 of rare occurrisnce and inhabiting only districts which are comparatively inacces- 

 sible and not yet by any means thoroughly explored, zoologically — remained for so 

 many years unknown, until by a, happy chance it was sent down to the South 

 Australian Museum, and its existence made known by Dr. Stirling. There, 

 perhaps, yet lemains to be discovered in the remoter parts of the continent some 



